Dramatic Response to Therapeutic Plasma Exchange in Acute Transverse Myelitis following Dengue Fever

A Case Report

Abstract

Dengue is a mosquito-borne viral disease which has reached fearsome proportions in the past few years. Acute transverse myelitis (ATM) is a rare complication of dengue characterized by onset of bilateral lower limb weakness, paresthesia, and urinary retention and magnetic resonance imaging of the whole spine shows diffuse areas of abnormal hyperintensity on T2-weighted images involving the cord in the cervical and the dorsal region extending up to the level of conus. Treatment is usually steroids, intravenous immunoglobulin, and therapeutic plasma exchange (TPE). We report a case of ATM in a young male patient who was successfully treated by TPE.

INTRODUCTION

Dengue, an acute viral fever transmitted by Aedes mosquito, is highly endemic in many tropical and subtropical areas of the world.[¹] Presenting features may range from asymptomatic fever to dreaded complications such as dengue hemorrhagic fever and dengue shock syndrome. A wide variety of neurologic complications might result from dengue fever like encephalopathy, meningitis, myelitis, cranial and peripheral neuropathy, Guillain–Barré or Miller–Fisher syndromes, and hypokalemic paralysis.[²] Acute transverse myelitis (ATM) is a rare complication of dengue fever. ATM is a heterogeneous inflammatory disorder affecting the spinal cord at one or more segments.[³] ATM following dengue fever treated by therapeutic plasma exchange (TPE) is rarely reported in the literature. We report a case of ATM after dengue infection recovered by TPE.

CASE REPORT

A 25-year-old male presented with sudden onset bilateral lower and upper limb weakness, paresthesia, and urinary retention after 5 days of the onset of dengue infection. Complete blood count showed hematocrit of 45% and platelet count was 140,000/uL. Dengue NS1 antigen was positive. Normal bilirubin levels with a mild rise in enzymes (serum glutamic-oxaloacetic transaminase and serum glutamic-pyruvic transaminase) were found in liver function test. Viral markers (HIV, hepatitis B surface antigen, and hepatitis C virus) were negative. Cerebrospinal fluid (CSF) analysis depicted lymphocytosis, adenosine deaminase was 11.6 μ/L, and CSF protein was mildly raised. Test for antinuclear antibodies was negative. Anti-AQUAPORIN-4 by indirect immune florescence test was also negative. After a complete physical examination and detailed investigations, a diagnosis of ATM due to dengue fever was made. Magnetic resonance imaging of the whole spine showed diffuse areas of abnormal hyperintensity on T2-weighted images involving the cord in the cervical and the dorsal region extending up to the level of conus, which confirmed the diagnosis of ATM [Figure 1]. On Central Nervous Examination (CNS) examination, deep tendon reflexes were elicited and there was hypotonia and paresthesia in both lower limbs and upper limbs [Table 1]. Distal tendon reflexes were normal in the upper limbs (biceps, triceps, and supinator) and absent in both lower limbs (knee and ankle). Plantar reflexes were bilaterally absent. He was managed with intravenous (IV) methylprednisolone 1 g intravenously daily for 1 week followed by oral tablets. However, there was no appreciable improvement in motor power, so TPE was planned after taking informed consent from the patient. All Five sessions of plasma exchange were conducted on alternate days. All procedures were done using Haemonetics Multi Components System (MCS)®+ (Haemonetics MCS +) through femoral line as vascular access. One plasma volume was performed, which corresponds to 2800 ml according to the weight and hematocrit of the patient. Group-specific fresh frozen plasma was used as a replacement fluid. All TPE procedures were uneventful. Follow-up was done and the patient was instructed for physiotherapy and bladder training and the patient recovered gradually [Table 1].

Figure 1: Magnetic resonance imaging T2-weighted images shows hyperintensity of the spinal cord in transverse section IA-cervical (C3 to C7), IB-thoracic level (T1 to T12) and IC-axial T2 image involving spinal cord the cervical region

Table 1: Improvement in patient after therapeutic plasma exchange

DISCUSSION

Dengue fever is an acute viral disease and its incidence has increased in last few years. Although neurological complications of dengue infection have been observed, spinal cord involvement in the form of transverse myelitis is extremely rare.[⁴] Isolated reports are the tip of the iceberg. Most acceptable theories for pathogenesis include the neurotropic effect of the virus or the immune mediated injury or both. When the neurologic symptoms develop in preinfectious period, it is attributed to direct viral invasion of the nervous tissue. Delayed appearances of neurologic disorders usually in postinfectious phase are considered to be due to immunologically mediated neural injury.[⁵] The diagnostic criteria are based on the Transverse Myelitis Consortium Working Group 2002, which includes motor, sensory, or autonomic dysfunction attributable to spinal cord.[⁶] The main stay of treatment is to reduce the spinal cord inflammation and manage the symptoms. Initial treatment includes IV corticosteroids such as methylprednisolone for a period of 5 to 7 days. People who are refractory to steroids/IV immunoglobulin (IVIG) respond well to TPE[⁷] IVIG is a costly treatment and most of the patients from Asian countries cannot afford. According to American Society for Apheresis 2019, TPE for ATM comes under category II. Therapeutic plasma exchange is an effective rescue therapy to reduce circulating auto antibodies of the patients. Our patient was treated with IV corticosteroids, TPE, and physiotherapy, and the outcome was favorable and the patient had complete recovery.

CONCLUSION

ATM should be diagnosed as soon as possible. If an autoimmune aetiology is suspected, prompt administration of TPE should be considered. TPE may be an effective therapy or complimentary therapy along with steroids in these patients. Timely institution of TPE can fasten recovery.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.